The surviving spouse is exempt in most cantons, and direct descendants are also exempt in many cantons. “Most” is not “all”, so check the target canton before building a succession plan around the assumption.
certain prior benefits can be brought into inheritance-tax treatment
Lucerne and Neuchâtel
relevant prior gifts within five years in the cited rules
Solothurn
relevant where brought back into the estate for equalisation
Geneva
gifts to an heir can remain relevant without a time limit; certain other beneficiaries use a five-year period
These rules are technical and fact-sensitive; use the table as a planning trigger, not a substitute for cantonal advice.
Combine inheritance tax with wealth tax
A canton that is attractive on succession can be expensive over 20 years of annual wealth taxation. A canton with no tax on descendants may still tax unrelated heirs heavily.